Bathythermograph



March 1, 1955 Filed Nov. 28, 1945 W. M. EWING ETAL BATHYTHERMOGRAPH ill 4 Sheets-Sheet 1 INVENTORS WILLIAM M. EWING ALLYN Q. VINE ATTORNEY March 1, 1955 w. M. EWlNG ET AL BATHYTHERMOGRAPH 4 Sheets-Sheet 2 Filed Nov. 28, 1945 aze 67540 7 gwuentow W/u/AM M WW6 Skim;

March 1 1955 W. M. EWING ET AL BATHYTHERMOGRAPH 4 Sheets-Sheet 3 Filed Nov. 28, 1945 0 g 1N VENTORS CON 0 m M 3 3 l March 1, 1955 W.'M. EWING ET AL BATHYTHERMOGRAPH 4 Sheets-Sheet 4 Filed Nov. 28, 1945 FIG. 6.

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DEGREES FAHRENHEIT 5T INVENTORS M. EWING ALLYN 6. VINE ATTORNEYS WILL/AM United States Patent BATHYTHERMOGRAPH William M. Ewing and Allyn C. Vine, Woods Hole, Mass., assignors to the United States of America as represented by the Secretary of the Navy This invention relates to apparatus for carrying out bathic determinations which may be employed especially in connection with the operation of submarines. More particularly, the invention is concerned with temperatures, hydrostatic pressures, and density conditions at different ocean depths, and with the effect of these factors on the diving characteristics of submarines, as well as the sonic properties of water at various depths.

In one specific aspect the invention deals with a submarine bathythermograph adapted to produce a record of information useful in controlling ballast adjustments such as are necessary to maintain a submarine in trim, i. e. in a state of neutral buoyancy, when the weight of the submarine is adjusted to equal the weight of the displaced water.

In determining the ballast changes required at different depths to maintain trim, it is necessary to take into consideration the changes in the density of isothermal water at varying depths, changes in density of the submarine owing to compressibility of its hull, and changes in the density of water which varies in temperature at different depths.

These variables react differently with respect to ballasting requirements. Thus, if a submarine dives in isothermal water in which temperature remains substantially constant at all depths, it becomes necessary to pump out ballast sufiicient to compensate for the greater compressibility of water. On the other hand, if a submarine dives in water in which the temperature falls with increasing depths, it may be necessary to flood in ballast to compensate for the greater density of the colder water relative to the density of the submarine hull.

One application of our invention is based upon a recognition of the fact that when the amount ofwater ballast required to be flooded into a submarine, due to a temperature drop of the water in which the submarine is supported, just equals the amount of water ballast required to be pumped out due to pressure increase, the trim of the submarine will be unchanged. Charts representing the various pressures and temperatures at which trim is constant may therefore be prepared.

We have devised apparatus for observing temperature and depth changes directly from a moving submarine, and we have further discovered a way of correlating such temperatures-depth data with ballast changes by means of which there can be made a prediction of the effect of temperature and depth on ballast changes to be made in the operation of a submarine when moving from place to place, in directions either vertical or horizontal.

We have further devised a novel recording chart carrying indicator lines referred to as isoballast lines, which at various temperatures and depths denote temperature gradients which will provide a density layer exactly compensating for the effect of hull compression.

An important feature of the invention therefore is that it provides observation of temperature and depth change from a moving submarine, which temperature and depth are recorded as two preferably rectangular coordi nates on a chart.

Another feature of the invention is that it provides a temperature-depth trace which by its general shape indicates whether a submarine is very heavy or very light at different depths, and which may be interpreted at a lance. g Another feature of the invention is that the temperature and depth observing and recording meanshas a system of isoballast lines I inscribed on the recording 2,703,009 Patented Mar. 1955 chart. The isoballast lines indicate for various temperatures and depths the particular temperature gradients that will exactly compensate for the effect of hull compression. The isoballast lines may be of several types. One type is suitable for a quick change in depth where it is desired to know the effect on trim before the submarine gets to the same temperature as the water. Another type is provided, applicable when the submarine hull and contents have reached the temperature of the surrounding water.

Another feature of the invention is that the isoballast lines on the chart are so spaced that any deviation of a temperature depth trace from an isoballast line may be instantly interpreted to indicate the number of pounds of ballast which must be flooded in or pumped out to maintain trim. The typical card is made up so that the interval between any two isoballast lines represents a ballast change of 2000 pounds. After the family of isoballast lines is established, the only additional information needed to determine a convenient spacing is the weight of the submarine.

Another feature of the invention is that it can be used in denoting when the density of water increases with depth faster than the density of the submarine. From this it is readily determinable when and at what depths a submarine can balance in the water with all propulsion stopped and without ballast adjustments. This maneuver is of great value in military operations for quietness, conservation of power, and safety in case of mechanical failure.

Another feature of the invention is that it can be used in determining the effect of water pressure on the diving characteristics of a submarine. One of the most important of these is a determination of the compression of the hull which can be quickly arrived at with the aid of the information on the chart. The exact value of hull compression is a matter not heretofore measured and is of great interest in designing submarines and in comparing different types of submarines.

Still another feature is that the temperature-depth trace made by use of the invention can be interpreted to show the effects of temperature on the transmission of sound in sea Water. It is possible in this Way to determine at what depth a submarine would be safest from acoustic detection. The trace also gives by suitable interpretation the relative safety at different depths.

Other features involving further operations and novel construction of a submarine bathythermograph will appear in the following description.

In the accompanying drawings:

Fig. 1 is a representation of the bridge and conning tower of a submarine with our new instrument arranged therein in a preferred manner;

Fig. 2 shows in detail the temperature bulb;

Fig. 3 is a perspective view of the indicating and recording mechanism;

Fig. 4 is an end elevation showing the device as it would appear to an observer;

Fig. 5 is a diagrammatic view of a bathythermograph trace;

Fig. 6 is a view illustrating a recording chart of the inviention showing one series of iso-ballast lines thereon; an

Fig. 7 is another elevational view of a recording chart carrying a trace inscribed over another series of isoballast lines thereon.

The apparatus illustrated in the drawings comprises a preferred embodiment of the invention.

Included in the apparatus referred to are mechanical means for observing temperature changes occurring in water outside of a submarine hull during diving operations; mechanical recording means for translating temperature and depth changes into visual indications in the form of a curve or trace as shown in Figs. 5 and 7; recording charts or cards which are ruled with uniformly spaced vertical and horizontal lines constituting temperature and depth coordinates, and on which the temperature-depth trace is inscribed; and isoballast lines as shown in Figs. 6 and 7 which may also be drawrr'on the recording charts and which represent for various temperatures and depths temperature gradients along which a submarine will be in trim.

The general plan or method of utilizing this equipment is to establish, in terms of pressure and temperature, a curve or path on the record chart which forms acharacteristic pattern of adive in isothermal water. This is essentially a vertical line running from the top to the bottom of one of the recording charts or cards above referred to.

In non-isothermal water the temperature changes which are measured by the bathythermograph are then translated by the recording means of the invention so that they appear as a pattern or trace which deviates from the path followed by a trace of a dive in isothermal water.

The manner of deviation then becomes highly significant. For example, if the bathythermograph records a large. drop in temperature with increase in pressure or depth, the trace tends to move indirections both vertically downward and: to' the left of an operator facing a chart, indicating that the submarine is light. If the bathythermograph records an increase in temperature, which may happen in afew instances, the trace will move downwardly in a direction to the right of the observer, indicating that the effect of this temperature change is to make the submarine heavy. When the submarine bathythermograph records no temperature change during diving operations, the trace will appear as a vertical straight line. In Fig. 5-, we have diagrammatically indicated' changes in direction of a submarine bathythermograph trace resulting from passing through different kinds of layers.

Inaddition, the application of the invention involves the use of isoballast lines. These lines indicate temperature gradients along which at varying depths a submarine will always be intrim. Plotting of isoballast lines is carried out from data assembled from diving operations, carried out in water Where the variation of density with depth is measured and the changes in trim at various depths are noted. They are adapted to be drawn on the same chart or card which is employed to form the temperature-depth trace of the submarine bathythermograph, and preferably they are spaced apart distances representing percentages of the weight of the submarine, thus denoting. the ballast change required for trim along any particular temperature-depth gradient (Fig. 6). The deviation of a. submarine bathythermograph trace with respect to isobal last lines at any given point thus becomes exceedingly informative from the standpoint of checking on diving levels and adjustment of ballast for maintaining trim.

For example, Fig. 6 illustrates an iso-ballast chart containing iso-ballast lines for a submarine which displaces 2400 tons when submerged and which is required to pump or eject 6000 pounds weight of water in order to increase its submerged. depth 100 feet in iso-thermal water.

The series of iso-ballast lines as illustrated at 1B in Figure 6 are arranged and inscribed so that they pass through a series of points indicating all conditions of temperature and distances of depth in which that submarine, for which the chart of Figure 6 is designed, can remain in trim (or in neutral buoyancy) without changing ballast.

For instance, if by some freak of chance a bathythermograph' trace of the type shown at ET in Figure 7 should instead follow exactly on or in a path parallel to the adjacent iso-ballast line of its chart, such as line 13 in Figure 7, it would then be theoretically possible that once that submarine had made such an even trace was in trim at any depth, it could go to any depth without pump ing or flooding ballast water;

Accordingly, it will be. seen that each of the iso-ballast lines inFigures 6 and 7 are all spaced apart at distances indicating. differences in ballast of an additional 2000 pounds each in. weight of water.

A further example is illustrated in Figure 7. trates an iso-ballast. chart for another submarine which displaces 2400 tons when submerged, but which is required'to pump or. eject 2000 pounds weight of water in order to increase its submerged depth 100 feet in isothermal water; Here it may be assumed that a submarine starts at' 100" feetsubmerged depth and is in trim. Thisis shown on the chart in Fig. 7 at the first of the two points where the trace BT intersects the iso-ballast line IE.

it illus- A.

In other words, that submarine could dive under power to ti depth of 2'10 feet and again remain in trim at that point (the second intersection of lines BT and 13) without pumping or flooding.

For instance, if that submariner had desired to remain in trim at 200 feet, he would have had to pump about 1600 pounds weight of water. This appears on the chart as about .8 of the distance to the right between the two adjacent iso-ballast line's IB and IB".

Or, if he wishedto go to 2-30 feet depth and remain in trim, he would have to flood about 6000 pounds weight of water. This appears on the chart as about 3' spaces between the iso-bal last line 13 and the iso-ballast line IB as shown in the chart of Figure 7.

Considering in greater detail the apparatus of the invention, Fig. 1 indicates the relationship of the various parts. Numeral 1 denotes the bridge of a submarine. Within the vessel at a location convenient for observation by the operating personnel, is mounted the indicating and recording mechanism of our bathythermograph 2. The operation of the instrument is caused by temperature input from the bulb 3 and pressure input taken from, for example, the line to the ves'selsregular depth gauge 4. In the instance herein described, the operating elements 10 and- II are Bourdontubes actuated by pressure caused by thermal expansion or contraction of the liquid in bulb 3 and by variations of hydrostatic pressure affecting the pressuregauge 4-, respectively.

Shown one or more of Figures 3 and 4 are the details of the indicator-recorder 2. The various elements are mounted upona base 9. Temperature Bourdon 10 is mounted onsub-base 9a with its axis vertical to the base 9, one end of the helix being secured against rotation except as required for zero adjustment. Pressure Bourdon 11 is secured similarly, with its axis parallel to the base 9.

Referring to the pressure indicating assembly 12, arms 13, 13 are pivotally mounted, one at each end of the helical tube 1 1 and with the common pivot 17 axially disposed relative to the helix. At the rear end the arms 13, are connected by counterweight 14, while at the forward end they are connected by plate 15, which serves as asupport for the record card- 16. The free end of Bourdonv 11 is secured to the pivot shaft 17, and the arrangement is suchthat expansion or contraction causes rotation of pressure indicator 12 constituted by arms 13, 13, counterweight- 14', and plate 15.

With reference to the temperature indicator 21, stylus arm 18 with balance weight 26 is secured to a pivot shaft 19 axially disposed relative to Bourdon 10, the free end of which is fastened to the shaft 19 so that rotating movemerit-may be transmitted thereto. Stylus arm 18 projects above plate 15 and flexible stylus 20 is secured to arm 18 so as to be substantially parallel to plate 15 and thus in recording relation to card 16.

Temperature; bulb 3, shown particularly in Figure 2, is mounted outside the hull in cont-act with the water. It comprises, in this instance, an adequately long, small gauge metal tube 22' closed at one end, and filled with some fluid such as xylene. This tube is supported for free access by the surrounding water, by being wound about a finned projection 24' from base 23, and is protected by a perforated cover 25.

A- continuation of tube 22 projects through a suitable gland or stutfing box 6 into the interior of the vessel, is in liquid communication with Bourdon element 10, and constitutes the means whereby the pressure of the liquid is transmitted thereto.

The vessels depth gauge 4 is here assumed to be of the type-wherein depths are indicated by means including a Bourdon tube actuated by liquid under the hydrostatic pressureof the water in which the vessel operates. Where itis operated from this systemor by separate means, liquid under pressure in line 8 is in communication with Bourdon tube 11. Changes in pressure, corresponding to changes in depth, will cause Bourdon 11 to contract or expand, this movement being translated into rotary motion of pivot shaft 1 7 Plate 1 5 is shown as being part of a box-like structure 27, and as having intumed' projections 23', 23 at top and bottom edges for holding card 16 which may be inserted and removed from the end. Lighting. means may be pl'ac'edbehind plate- I5 and plate I S'may; be partially cut away as shown, so that the card 16 is illuminated The lighting means is not shown, but may be of any desired type.

A cover (not shown) may be provided for protection. It is intended that the recoruing and indicating device 2 be suitably mounted on bulkhead or overhead for easy observation.

On first installation, calibration may be accomplished by observing water pressure and temperature and adjusting the clamp as provided on the base of each of the Bourdons and 11, respectively, so that stylus positions properly with respect to the grid markings of card 16.

As the temperature of the water in which bulb 3 is immersed varies, stylus 20 moves corresponding in a horizontal plane. The flexibility of stylus 20 accommodates the arcuate movement of arm 18 about axis 19. Pressure variations cause vertical movement of box 27 with card 16. At any given instance, therefore, pressure (or corresponding depth) and temperature may be observed. In Figure 4, for example, depth is 245 feet, temperature 65 F. Ordinarily stylus 20 will mark card 16, as by a pen or pencil, thus giving a permanent record, say for one dive of the submarine.

A typical depth trace is shown on a card with isoballast lines in Fig 7. It is seen that the temperature is about 77 F. from surface to 200 feet. From that depth to 260 feet it decreases uniformly to 58, and then remains constant to 450 feet.

Without isoballast lines, the following deductions would be possible:

(a) Sound transmission would be of different type at points from surface to 200 feet than it would be below 260 feet.

(b) To keep the ship in perfect trim during a dive, it would be necessary to pump out ballast down to 200 feet; probably necessary to flood in ballast to 260 feet; and necessary to pump out ballast below that depth. The uncertainty about the interval between 200 and 260 feet arises from the fact that in this interval the change in temperature produces an effect which is opposite to the effect of changing depth, and the most direct way to find which efiect prevails is to use the isoballast lines. At a glance one can see that balancing is impossible except between 200 and 260 feet, and that balancing is probably possible in this interval.

By use of the isoballast lines in Fig. 7,, quantitative information about ballast requirements and diving conditions may be obtained. For instance, if a submarine is in trim at 100-foot depth in Fig. 7, and descends without ballast changes, the following situations will exist:

(a) Between 100 and 200 feet, submarine is heavy and grows heavier, reaching a maximum of about 2000 lbs. heavy at 200 feet.

([1) From 200 feet to 210 feet, the submarine is heavy but growing lighter, reaching neutral buoyancy or perfect trim at 210 feet.

(0) From 210 feet to 260 feet, the submarine is light and growing lighter, reaching a maximum of about 12,000 lbs. light at 260 feet.

v(d) From 260 feet to 450 feet, the submarine is light but growing heavier At 450 feet it is only about 8000 lbs. light.

It will be seen that we have provided apparatus for making bathic determinations which greatly facilitate and aid in operation of submarines, especially in connection with military maneuvers. The apparatus is readily utilized and adaptable for installation in submarines with a minimum of expense and interference with the normal functioning of a submarine. The use of the apparatus generally furnishes a starting point for computing various data relating to ocean depths, and provides a means of studying compression characteristics of submarines, as well as sonic properties of water.

We claim:

1. Indicating and recording bathythermograph apparatus comprising in combination in a submarine: a recording bathythermograph mounted in the interior of said submarine; pressure responsive means mounted in the interior of said submarine; temperature responsive means mounted on the exterior of said submarine; said bathythermograph comprising; a relatively horizontal base member; a first helical Bourdon tube mounted to rotate on an axis vertical to said base; said first tube being in operating communication with said temperature responsive means; a second helical Bourdon tube mounted to rotate on an axis parallel to said base; said second tube being in operating communication with said pressure responsive means; cradle means fixed to said parallel axis and mounted to rotate therewith; a record element held by one end of said cradle in a position perpendicular thereto to travel therewith in an arc; a marking arm fixed to said vertical axis and mounted to rotate therewith and to extend beyond the arc of movement of said record element; a marking element fixed to one end of said marking arm and positioned to mark a trace upon said record element during their concurrent motions.

2. The combination of claim 1 wherein said record element includes a chart comprising: a series of temperature-graduated horizontal coordinates and depth-graduated vertical coordinates; iso-ballast lines for said submarine inscribed across said coordinates; each of said iso-ballast lines being inscribed to indicate temperature gradients along which said submarine will always remain in trim in varying density layers in iso-thermal water; said isoballast lines being spaced apart at intervals each repre senting an equal percentage of the weight of said submarine.

3. A bathythermograph comprising; a relatively horizontal base; a first Bourdon tube mounted to rotate on an axis vertical to said base; a second Bourdon tube mounted to rotate on an axis parallel to said base, one of said tubes being responsive to changes in temperature; the other of said tubes being responsive to changes in pressure; a record arm fixed at right angles to one of said axes for rotation therewith; a marking arm fixed at right angles to the other of said axes for rotation therewith and positioned in operating relationship with said record arm; record means on one end of said record arm; marking means on the adjacent end of said marking arm; whereby said marking means moves always at right angles to the motion of said record means and whereby both of said last named means move in substantially the same plane to inscribe a trace upon said record means.

References Cited in the file of this patent UNITED STATES PATENTS 472,266 Kindl et al. Apr. 5, 1892 694,153 Holland Feb. 25, 1902 1,131,712 Klein Mar. 16, 1915 1,190,614 Williams July 11, 1916 1,373,329 Hoar Mar. 29, 1921 1,402,803 Smith Jan. 10, 1922 1,481,230 Rovetto Jan. 15, 1924 1,797,502 Hall Mar. 24, 1931 1,906,806 Plesch May 2, 1933 2,165,744 Boettinger July 11, 1939 2,297,725 Spilhaus Oct. 6, 1942 2,331,810 Spilhaus Oct. 12, 1943 2,396,724 Spilhaus Mar. 19, 1946 FOREIGN PATENTS 281,485 Germany Jan. 9, 1915 

